Immunohistochemistry of FSHβ and LHβ cells and their gene expression in the pituitary around gonadal differentiation in red spotted grouper Epinephelus akaara and blacktip grouper E.fasciatus
XU Wengang, LIU Liming, WANG Jiulong, YU Wensong, SUN Ming, SOYANO Kiyoshi, TANG Yongzheng
1.School of Ocean, Yantai University, Yantai 264005, China; 2.Yantai Institute of Marine Economy, Yantai 264003, China; 3.Shandong Modern Fisheries Corporation, Yantai 264003, China; 4.Institute for East China Sea Research, Organization for Marine Science and Technology, Nagasaki University, Nagasaki 851-2213, Japan
Abstract: Follicle stimulating hormone(FSHβ)and luteinizing hormone(LHβ)cells in the pituitary were identified and localized in 50, 80, and 120 days post hatching(dph)red spotted grouper Epinephelusakaara and blacktip grouper E.fasciatus by immunohistochemistry with hematoxylin-eosin staining and the fshβ and lhβ mRNA content was detected by qRT-PCR to evaluate gonadal differentiation, pituitary structures and FSHβ and LHβ gene expression.The results showed that the early gonadal development in the two species was divided into undifferentiated stage, differentiated stage, and ovarian stage, with undifferentiated stage at location around the gut with germ cells and blood vessels at 55 dph and differentiated stage at 80 dph.The ambilateral connective tissue of gonadal primordium gradually developed forward and two slight protuberant aggregations appeared, indicating that the ovarian cavity was formed.The 120 dph red spotted grouper and blacktip grouper had ovary stage, with complete ovarian cavity and the oogonia, indicating that the sex of groupers had differentiated into female.The two species of fish had similar pituitary structures consisted of neurohypophysis and adenohypophysis which was further divided into three minor parts including the rostral pars distalis(RPD), proximal pars distalis(PPD), and the pars intermedia(PI).The immune signals of FSHβ and LHβ were mostly detected in the PPD area, with a few signals detected in the RPD or PI area at 50, 80, and 120 dph in the two species.There was significantly higher fshβ mRNA content at 120 dph than that at 50 and 80 dph(P<0.05), without significant difference in lhβ content at 50 and 80 dph(P>0.05).The blacktip grouper had significantly higher fshβ and lhβ content at 120 dph than the blacktip grouper did at 50 and 80 dph(P<0.05).The findings indicated that gonadal differentiation was finished at 120 dph in the two species of groupers.The pituitary structures were completely formed at 55 dph, and FSHβ and LHβ played important roles during gonadal differentiation.
徐文刚, 刘立明, 王九龙, 于文松, 孙明, 征矢野清, 唐永政. 两种石斑鱼性腺分化前后脑垂体中FSHβ和LHβ细胞免疫组织化学及其基因表达[J]. 大连海洋大学学报, 2021, 36(4): 554-562.
XU Wengang, LIU Liming, WANG Jiulong, YU Wensong, SUN Ming, SOYANO Kiyoshi, TANG Yongzheng. Immunohistochemistry of FSHβ and LHβ cells and their gene expression in the pituitary around gonadal differentiation in red spotted grouper Epinephelus akaara and blacktip grouper E.fasciatus. Journal of Dalian Ocean University, 2021, 36(4): 554-562.
2021, Vol. 36 
